<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div class="loading">Loading</div>
  <script>
    let loading = document.querySelector(".loading");
    let letters = loading.textContent.split("");
    loading.textContent = "";
    letters.forEach((letter, i) => {
      let span = document.createElement("span");
      span.textContent = letter;
      span.style.animationDelay = `${i / 5}s`;
      loading.append(span);
    });
  </script>
</body>
<style>
body {
  display: flex;
  height: 100vh;
  justify-content: center;
  align-items: center;
  text-align: center;
  background: #2980b9;
}

.loading {
  display: flex;
  color: white;
  font-size: 3em;
  text-transform: uppercase;
}

.loading span {
  padding: 0 20px;
  line-height: 100px;
  background: #34495e;
  animation: bulge 2s infinite;
}

@keyframes bulge {
  50% {
    box-shadow: 0 20px 0 #eee;
    transform: translateY(-35px);
  }
}
</style>
</html>